I. Preoperative treatment standardization 1. Preoperative preparation: ① Ideological preparation, do a good job of explaining to the patient and his family, explaining the importance and superiority of deep vein cannulation, so that the patient fully recognizes and understands the purpose of the operation and the risks. ② Vascular preparation, preferred right internal jugular vein, such as previous deep vein cannulation, vascular ultrasound to understand the presence of vascular stenosis and wall thrombus, if there is a vascular abnormality, then replace the puncture site. Surgical consent form should be signed on the basis of full communication with patients and their families. The surgical consent form should not be copied from the template, but must be modified on the basis of the template in combination with the patient’s specific condition to meet the patient’s actual condition, and the consent form should be read in full by the signer or the doctor should read it in full to the signer to make sure that the signer knows the significance of the surgery and the risk. Chen Feng, Department of Nephrology, Xinqiao Hospital, Third Military Medical University 2. Precautions: General contraindications to deep venous cannulation include localized infection or thrombosis of the puncture vein. An experienced physician must be present for deep vein cannulation. Deep vein cannulation should be performed under ultrasound guidance in those with anatomical abnormalities. 3. Qualification of the operator: Only those who are qualified to perform the procedure, as announced by the department, are allowed to perform the procedure. Otherwise, it is regarded as violation of medical operation regulations. According to the patient’s condition and whether he/she is able to cooperate with the position, deep vein cannulation should be performed via internal jugular vein, subclavian vein and femoral vein respectively. Transjugular vein puncture: (1) The patient should be placed in the supine position with a small pillow under the shoulder and the head tilted back and to the left side to fully reveal the sternocleidomastoid muscle. (2) Disinfect, spread a sterile towel, and anesthetize with 2% procaine or lidocaine local infiltration. (3) The puncture point was chosen to be the tip of the triangle formed by the sternal head and clavicular head of the lower end of the sternocleidomastoid muscle, and the puncture needle was placed at an angle of 15 degrees to 30 degrees to the skin, with the tip of the needle pointing to the ipsilateral nipple, and then punctured into the internal jugular vein, which was confirmed to be venous. (4) Insert the guidewire and withdraw the needle. (5) Insert the deep venous catheter into the vessel along the guidewire and withdraw the guidewire outward while feeding the intravenous catheter until the guidewire is exposed from the end of the catheter. (6) If venous blood is confirmed by retraction, the puncture is successful. (7) Fix the catheter properly and seal it with heparin. 2. Transclavian vein puncture: (1) Take the supine position with the shoulder lifted up and abducted. (2) Disinfect, lay a sterile towel, and apply local anesthesia. (3) Choose the midpoint of the clavicle as the puncture point. The tip of the needle is pointed at the midpoint of the line between the sternoclavicular joint and the inferior border of the thyroid cartilage, and the needle is inserted at an angle of 15 degrees to the skin, reaching the subclavian vein in about 2 to 4 cm. (4) The rest of the procedure is the same as that of internal jugular vein puncture. Transfemoral vein puncture: (1) The patient lies on his/her back, and the right lower limb is externally rotated and adducted. (2) Routine disinfection and laying of towel, local infiltration anesthesia, in the inguinal ligament 2 cm below the midpoint of the femoral artery, the femoral artery is obvious, the needle is inserted in the medial part of the femoral artery, the needle is at a 45-degree angle to the skin, and the tip of the needle is pointed to the umbilicus, and the needle is fixed when the venous blood is extracted from the vein. (3) The rest is the same as internal jugular vein puncture. (4) Double lumen with polyester sleeve long-term indwelling tube insertion: the right internal jugular vein is preferred, the patient is lying down, the back of the shoulder is padded with pillow, the head is tilted back by 15 ° ~ 30 ° and turned to the left side, and the middle and lower part of the triangle of the sternocleidomastoid muscle is the puncture point, the seldinger technique is used to place the guidewire, and then the position of the tunnel and the opening of the tunnel are determined by marking on the surface of the body, and then the patient cuts an incision of 0.5 cm by a scalpel, and then bluntly separates it and pulls the catheter from the tunnel by a retracting needle. A 0.5 cm incision was made with a scalpel, bluntly separated, and the catheter was pulled by a retractor needle from the incision into the subcutaneous tunnel to reach the puncture point, and the catheter was placed into the internal jugular vein using a tear-type dilatation catheter placement method, and the tip of the catheter was placed in the right atrium or the junction of the superior vena cava and the right atrium. The subcutaneous tunnel was about 9~10cm, and the polyester sleeve was 2~3cm away from the skin outlet, and the catheter in the tunnel must maintain a good curvature to avoid catheter fracture. The catheter will be sent to the root of the superior vena cava repeatedly pumping test blood flow is good, and then respectively in the arterial and static vein lumen filled with 1:1 heparin saline, and finally suture the incision, fixed catheter position in the right side of the chest, static and dynamic catheter outer mouth covered with heparin cap, in order to prepare for dialysis use. Postoperative treatment standardization 1, observe whether there are complications: common complications include arterial puncture, hematoma, pneumothorax, hemothorax, cardiac arrhythmia and improper catheter position. Observe whether there is edema in the limb and neck on the puncture side, and if it is subclavian vein cannulation, pay attention to whether there is subcutaneous emphysema around the puncture point, and whether there is respiratory difficulty; 2. Bleeding: if there is bleeding at the fixation place of the suture, it is mostly because of the small blood vessels at the place of the suture and the suture should be dismantled, and the position of the suture should be changed; if there is blood seepage at the cannulation place, it is mostly because of the oversized incision, and the venous blood is leaking out along the periphery of the tubes, and the blood is seeping out at the direction of the general hospitalization and the doctor of cannula, and then a purse-string suture is performed. If there is a lot of bleeding, it should be considered as a venous tear, and if necessary, the deep venous cannula should be removed and pressure bandage should be applied; if the bleeding is bright red, it should be considered as an arterial injury, and must be handled by an experienced doctor.